gpiic_opb.c revision 1.1 1 /* $NetBSD: gpiic_opb.c,v 1.1 2003/10/06 16:15:46 scw Exp $ */
2
3 /*
4 * Copyright 2002, 2003 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Steve C. Woodford for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed for the NetBSD Project by
20 * Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 * or promote products derived from this software without specific prior
23 * written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 #include "locators.h"
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/device.h>
43 #include <sys/errno.h>
44 #include <sys/lock.h>
45
46 #include <machine/cpu.h>
47
48 #include <dev/wasabi_i2c/i2cvar.h>
49 #include <dev/wasabi_i2c/i2c_bitbang.h>
50
51 #include <powerpc/ibm4xx/dev/opbvar.h>
52 #include <powerpc/ibm4xx/dev/gpiicreg.h>
53
54 struct gpiic_softc {
55 struct device sc_dev;
56 bus_space_tag_t sc_bust;
57 bus_space_handle_t sc_bush;
58 uint8_t sc_txen;
59 struct i2c_controller sc_i2c;
60 struct i2c_bitbang_ops sc_bops;
61 struct lock sc_buslock;
62 };
63
64 static int gpiic_match(struct device *, struct cfdata *, void *);
65 static void gpiic_attach(struct device *, struct device *, void *);
66
67 CFATTACH_DECL(gpiic, sizeof(struct gpiic_softc),
68 gpiic_match, gpiic_attach, NULL, NULL);
69
70 static int gpiic_acquire_bus(void *, int);
71 static void gpiic_release_bus(void *, int);
72 static int gpiic_send_start(void *, int);
73 static int gpiic_send_stop(void *, int);
74 static int gpiic_initiate_xfer(void *, i2c_addr_t, int);
75 static int gpiic_read_byte(void *, uint8_t *, int);
76 static int gpiic_write_byte(void *, uint8_t, int);
77 static void gpiic_set_dir(void *, uint32_t);
78 static void gpiic_set_bits(void *, uint32_t);
79 static uint32_t gpiic_read_bits(void *);
80
81 static int
82 gpiic_match(struct device *parent, struct cfdata *cf, void *args)
83 {
84 struct opb_attach_args *oaa = args;
85
86 if (strcmp(oaa->opb_name, cf->cf_name) != 0)
87 return 0;
88
89 return (1);
90 }
91
92 static void
93 gpiic_attach(struct device *parent, struct device *self, void *args)
94 {
95 struct gpiic_softc *sc = (struct gpiic_softc *)self;
96 struct opb_attach_args *oaa = args;
97 struct i2cbus_attach_args iba;
98
99 aprint_naive(": IIC controller\n");
100 aprint_normal(": On-Chip IIC controller\n");
101
102 sc->sc_bust = oaa->opb_bt;
103
104 bus_space_map(sc->sc_bust, oaa->opb_addr, IIC_NREG, 0, &sc->sc_bush);
105
106 lockinit(&sc->sc_buslock, PRIBIO|PCATCH, "gpiiclk", 0, 0);
107
108 sc->sc_txen = 0;
109 sc->sc_i2c.ic_cookie = sc;
110 sc->sc_i2c.ic_acquire_bus = gpiic_acquire_bus;
111 sc->sc_i2c.ic_release_bus = gpiic_release_bus;
112 sc->sc_i2c.ic_exec = NULL;
113 sc->sc_i2c.ic_send_start = gpiic_send_start;
114 sc->sc_i2c.ic_send_stop = gpiic_send_stop;
115 sc->sc_i2c.ic_initiate_xfer = gpiic_initiate_xfer;
116 sc->sc_i2c.ic_read_byte = gpiic_read_byte;
117 sc->sc_i2c.ic_write_byte = gpiic_write_byte;
118
119 sc->sc_bops.ibo_set_dir = gpiic_set_dir;
120 sc->sc_bops.ibo_set_bits = gpiic_set_bits;
121 sc->sc_bops.ibo_read_bits = gpiic_read_bits;
122 sc->sc_bops.ibo_bits[I2C_BIT_SDA] = IIC_DIRECTCNTL_SDAC;
123 sc->sc_bops.ibo_bits[I2C_BIT_SCL] = IIC_DIRECTCNTL_SCC;
124 sc->sc_bops.ibo_bits[I2C_BIT_OUTPUT] = 1;
125 sc->sc_bops.ibo_bits[I2C_BIT_INPUT] = 0;
126
127 /*
128 * Put the controller into Soft Reset. This allows us to
129 * manually bit-bang the I2C clock/data lines.
130 */
131 bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_XTCNTLSS,
132 IIC_XTCNTLSS_SRST);
133 delay(10);
134 bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL,
135 IIC_DIRECTCNTL_SCC | IIC_DIRECTCNTL_SDAC);
136
137 iba.iba_name = "iic";
138 iba.iba_tag = &sc->sc_i2c;
139 (void) config_found(&sc->sc_dev, &iba, iicbus_print);
140 }
141
142 static int
143 gpiic_acquire_bus(void *arg, int flags)
144 {
145 struct gpiic_softc *sc = arg;
146
147 if (flags & I2C_F_POLL)
148 return (0);
149
150 return (lockmgr(&sc->sc_buslock, LK_EXCLUSIVE, NULL));
151 }
152
153 static void
154 gpiic_release_bus(void *arg, int flags)
155 {
156 struct gpiic_softc *sc = arg;
157
158 if (flags & I2C_F_POLL)
159 return;
160
161 (void) lockmgr(&sc->sc_buslock, LK_RELEASE, NULL);
162 }
163
164 static int
165 gpiic_send_start(void *arg, int flags)
166 {
167 struct gpiic_softc *sc = arg;
168
169 return (i2c_bitbang_send_start(sc, flags, &sc->sc_bops));
170 }
171
172 static int
173 gpiic_send_stop(void *arg, int flags)
174 {
175 struct gpiic_softc *sc = arg;
176
177 return (i2c_bitbang_send_stop(sc, flags, &sc->sc_bops));
178 }
179
180 static int
181 gpiic_initiate_xfer(void *arg, i2c_addr_t addr, int flags)
182 {
183 struct gpiic_softc *sc = arg;
184
185 return (i2c_bitbang_initiate_xfer(sc, addr, flags, &sc->sc_bops));
186 }
187
188 static int
189 gpiic_read_byte(void *arg, uint8_t *vp, int flags)
190 {
191 struct gpiic_softc *sc = arg;
192
193 return (i2c_bitbang_read_byte(sc, vp, flags, &sc->sc_bops));
194 }
195
196 static int
197 gpiic_write_byte(void *arg, uint8_t v, int flags)
198 {
199 struct gpiic_softc *sc = arg;
200
201 return (i2c_bitbang_write_byte(sc, v, flags, &sc->sc_bops));
202 }
203
204 static void
205 gpiic_set_dir(void *arg, uint32_t bits)
206 {
207 struct gpiic_softc *sc = arg;
208
209 sc->sc_txen = (uint8_t)bits;
210 }
211
212 static void
213 gpiic_set_bits(void *arg, uint32_t bits)
214 {
215 struct gpiic_softc *sc = arg;
216
217 if (sc->sc_txen == 0 && (bits & IIC_DIRECTCNTL_SDAC) == 0) {
218 printf("gpiic_set_bits: SDA low with no output enable\n");
219 bits |= IIC_DIRECTCNTL_SDAC;
220 }
221
222 bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL, bits);
223 }
224
225 static uint32_t
226 gpiic_read_bits(void *arg)
227 {
228 struct gpiic_softc *sc = arg;
229 uint8_t rv;
230
231 if (sc->sc_txen != 0)
232 printf("gpiic_read_bits: Read in output mode\n");
233
234 rv = bus_space_read_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL) << 2;
235 rv &= (IIC_DIRECTCNTL_SCC | IIC_DIRECTCNTL_SDAC);
236
237 return ((uint32_t)rv);
238 }
239